填空题Reading Passage 1 has seven paragraphs A-H. From the list of headings below choose the most suitable heading for each paragraph. Write the appropriate numbers (i-xi) in boxes 1-8 on your answer sheet. List of headings Ⅰ Obesity in animals Ⅱ Hidden dangers Ⅲ Proof of the truth Ⅳ New perspective on the horizon Ⅴ No known treatment Ⅵ Rodent research leads the way Ⅶ Expert explains energy requirements of obese people Ⅷ A very uncommon complaint Ⅸ Nature or nurture Ⅹ Shifting the blame Ⅺ Lifestyle change required despite new findings